With the mangled head bolt finally removed, it's time to see what differences there are in the '93 Diamante SOHC block. The front and rear are identical on the Montero and Diamante blocks. The first difference is on the driver side where the Montero block has an unused oil passage - perhaps utilized by the Chrysler cars:

The Diamante block does not have that passage - but it doesn't matter for our purpose. Note that two dowel pins are installed in the Diamante block, though.... and those are in the way of the Montero A/C bracket:

A few minutes with a grinder fixed that issue - note the beam band near the skirt for extra strength:

Everything needed now mounts on the driver side:

The main difference on the passenger side is the extra gusset in the block. Here's the Montero:

Here's the Diamante - note not only the gusset/knee that reinforces the area of the engine mount, but also the horizontal beam band near the skirt flange:

Everything needed mounts to this side just fine, with no modifications necessary:

So, it looks like this block is an even more bulletproof version of the 6G72 and a good choice for an upgrade path - certainly not an expensive one. <img src="/forums/images/graemlins/kewl.gif" alt="" /> The bores look good, so tomorrow I'll order pistons..... and wait some more. <img src="/forums/images/graemlins/baby.gif" alt="" />

I did pull some main bolts for comparison... Montero on the left, Diamante SOHC in the center and Diamante DOHC on the right:

The Montero and Diamante SOHC are identical, and the Diamante DOHC is the same size, except I suspect it's stronger. Since the Montero and Diamante SOHC bolts have a circular step seat under the bolt head, I think I'll have the saddle area milled a hair just to make sure the larger flange area of the DOHC bolts get a good seating area:

I still want to see if the 4-bolt main 3000GT studs supplied by ARP will work, though.

Frank